Field of the Invention
The present invention relates to a rotation angle detection device.
Description of Related Art
As a rotation angle detection device having a magnet installed onto a rotating shaft, which magnetically detects a rotation angle of the rotating shaft, a geared motor position detection device disclosed in, for example, Japanese Unexamined Patent Application, First Publication No. 2007-259608 is known.
The geared motor position detection device includes a sensor plate which is installed onto an output shaft. The sensor plate includes a bearing which is fitted to a D-shaped tip portion of the output shaft, and a sensor portion (a magnet forming pole magnetic fields of an N pole and an S pole) formed in a flange shape on an outer circumferential portion of the bearing (see FIG. 7 of Japanese Unexamined Patent Application, First Publication No. 2007-259608 below). The geared motor position detection device is configured to detect a rotation angle of the rotating shaft, based on a change in magnetic flux density detected by a magnetic sensor such as a Hall IC.